DATCP: Comments requested for special onion pesticide registration

MADISON – Comments are needed on a proposed special pesticide registration for control of volunteer potatoes and broadleaf weeds in fields planted to dry bulb onions.

The special registration proposed by the Department of Agriculture, Trade and Consumer Protection (DATCP), will allow growers to use Starane® Ultra on dry bulb onions for control of volunteer potatoes (plants that sprout from the previous year’s crop) and weeds such as chickweed, common purslane, common ragweed, and morning glory. Starane® Ultra contains the active ingredient fluroxypyr and is registered by Dow AgroSciences LLC, Indianapolis, Ind.

The special registration process allows states to register additional uses of pesticide products without prior federal approval. This provides states flexibility to meet local needs such as controlling a plant disease or insect outbreak or in this case, to control weeds that compete with a growing crop. Starane® Ultra is already currently registered in Wisconsin and is labeled for use in agricultural crops such as wheat, barley, oats, field corn, sweet corn, and grain sorghum. It is not currently labeled for use in onions.

The proposed special registration will allow two applications of 0.35 pints of Starane® Ultra per acre per season on emerged weeds or volunteer potatoes using ground or aerial application equipment. The type of equipment and application used will depend on the growth stage of the onions. Broadcast (over-the-top) applications may be made in the earlier growth stages of onions (2-leaf stage through 6-leaf stage), whereas applications beyond the 6-leaf stage must be made as a directed spray using drop nozzles to prevent crop injury. For optimum control of volunteer potatoes, the potatoes should be 4 to 8 inches tall. Broadleaf weeds must be less than 4 inches tall. The product cannot be applied within 42 days of onion harvest.

In addition, use of this product may help potato and tomato growers lessen potential impacts of late blight. Volunteer potatoes in dry bulb onion fields can serve as a source of the fungal pathogen that causes late blight.

The preliminary environmental assessment indicates that the proposed amendment will not require a full environmental impact statement. This special pesticide registration will expire December 31, 2012.

For a copy of the assessment, contact Matt Sunseri, DATCP, PO Box 8911, Madison, Wis, 53708-8911, (608) 224-4547 or review the assessment at the department Mon.-Fri., 7:45 a.m.–4:30 p.m., 2811 Agriculture Dr., Madison, 2nd floor. Comments received on or before 4:30 p.m., March 31, 2011 will become part of the preliminary environmental assessment record. Send comments to Matt Sunseri by mail at the above address or by email at matthew.sunseri@wisconsin.gov.